BigBlueButton should scale better but you need own servers. It’s an open centralized solution.
Anyway it’s still possible to offer more efficient implementation with P2P connections. You don’t need N-1 connections at every peer if you don’t care as much about latency. For example centralized solutions run totally fine with at least one indirection of traffic.
So you can construct different topology for each use case. As compromise however you only need to have roughly log(N) connections at each peer theoretically. Obviously synchronization gets much more complicated but scaling is not really an issue.
Hi antonis, n(n+1)/2, is not only for small available its for all possible. It is just not implemented in source code. I think that you could have code that know how many peers watching and split every time some broadcast for subgroups up. Like every 10 clients and with a backup on above for +5 of the next group.
My suggestion for an alternative to Zoom is Jitsi Meet. I first learned about it from the Free Software Foundation, as they use it and also offer a server that active members can use too. It also has support for Etherpad, which I have not used yet. I have never joined any of their meetings to understand how video feeds scale past single digits.